Maintenance teams are responsible for maintaining the operation of a system based on observations of users of the system or on messages originating from test devices built into the equipment to establish an equipment failure diagnostic, identify and locate system equipment failures, and if required, replace a failed item of equipment, in part or in full. The gathering of messages and observations serving to track down equipment failures is called maintenance management.
The invention also relates to a method of managing equipment maintenance.
The architecture of complex systems is in general based on information transfers between electronic equipment linked together by a communication network. The location of the equipment in the system sometimes complies with harsh specifications regarding dimensions, moreover, the equipment can be difficult to access and be from about ten centimetres to several hundred metres away: such is the case for example with equipment built into an airborne aeronautical system.
The electronic equipment built into a system comprises software and hardware components. This equipment in general possesses a configuration which fully identifies its components to the manufacturer of the item of equipment and to the system. The configuration takes the form of one or more identifiers which can be fixed to the item of equipment, such as for example wording on a tag stuck on the external surface of a wall of a housing protecting the item of equipment. The configuration of an item of equipment allows a maintenance team to replace a failed item of equipment with a new item of equipment comprising the same configuration or a configuration for which a manufacturer of the item of equipment can guarantee that the item of equipment which carries it operates in a manner compatible with the failed item of equipment. The configuration of an item of equipment also makes it possible to alert the manufacturer of the item of equipment as to the existence of a chronic failure of a type of its equipment. When the manufacturer is informed of all the failures encountered by its equipment while operational, this information allows it to note that a failure frequency for a type of this equipment is abnormally high. In this way, the manufacturer can pinpoint a weakness of a type of equipment and propose a corrective to the equipment of this type.
An applicable configuration of a system is a list consisting of configurations of the various items of equipment built into the system. The configuration of the equipment can alter over time, one then speaks of system configuration management which is based on equipment configuration management.
For systems designed before the 1970s, equipment configuration management could in general be described as “static”, that is to say the applicable configuration of a system amounted merely to a system configuration register, for example a document in paper form, which contained all the configurations of the items of equipment built into the system. Any alteration in a configuration of one of the items of equipment built into the system was recorded manually in the configuration register.
The static character of this type of configuration management exhibits the drawback of making it very irksome to carry out a final check of compatibility between the configuration of the equipment built into a system and the applicable configuration of the system. This check can take place for example at the time of a system startup, and serves to cover the risk consisting of erroneous replacement of a failed item of equipment by an item of equipment whose configuration is not in accordance with that recorded in the configuration register. The erroneous replacement takes place between two successive power-ups of the system: it must be detected as early as possible.
More recent design systems generally build in so-called “intelligent” maintenance management, one also speaks of “intelligent system”. “Intelligent” configuration management consists in storing the configuration of an item of equipment in a memory internal to the item of equipment. The configuration of the item of equipment is transmitted, while the system is powered, before anything else, to a main computer of the system, by means of a communication network. The communication network links, for example in a star, the main computer and the equipment of the system. The main computer verifies that the configurations that the equipment transmits to it are compatible with the system's applicable configuration which is stored beforehand in one of its internal memories.
In general, the equipment of “intelligent systems” comprises, furthermore, a built-in test device (known as “Built-In-Test Equipment” or by the acronym BITE). The built-in test device delivers, destined for the main computer, messages containing information on the operation of the item of equipment into which it is built, across the communication network. “Intelligent” maintenance management consists in centralizing in a nonvolatile memory MVN belonging to the main computer the messages describing operating anomalies of the equipment built into the system and in producing, on each shutdown of the system, reports summarizing these anomalies. The reports are stored in a nonvolatile memory of the item of equipment concerned so as to be usefully consulted therein by a maintenance team.
However, maintenance management of “intelligent equipment” suffers from a twofold drawback:
In general, it is possible to consult the anomaly report stored in a nonvolatile memory of the item of equipment solely when the item of equipment into which this memory is built is supplied with power and is linked to a communication network. When the item of equipment has been removed from the system by a maintenance team, either because it has been identified as having failed, or because the item of equipment is built into a system which is not supplied with power, the maintenance team must necessarily resort to a test bench to access the anomaly report relating to the item of equipment. A test bench is an installation which is devised to supply power to and access the content of the memories internal to the item of equipment. This installation is expensive and/or bulky and it is not always possible to transport the item of equipment rapidly to a test bench. The delay taken to access the anomaly report can impinge directly on the duration of unavailability of the item of equipment, and may generate a duration of system unavailability which may turn out to be very expensive.
In the prior art, the information which is transmitted in the upward direction, that is to say the messages delivered by the built-in test devices of the equipment and received by the main computer of the system comprise a summary of the results of tests carried out by the built-in test devices. This choice aimed at reducing the volume of data transmitted is dictated in general by limitations related to the maximum information throughput of the communication network, to the reduced capacity of nonvolatile memories. Certain test results relate exclusively to the equipment such as for example, those corresponding to internal location of the fault within the item of equipment or to the local context of the failures, and others being specific, such as for example technical data for the instrumentation of the equipment supplier: these messages are not used by the main computer, it is not necessary to transmit them to it.
For these various reasons, the upward messages therefore do not comprise all the information produced by the built-in test devices. Nevertheless, it may be very instructive, for a maintenance team which has extracted an item of equipment from a system, to ascertain all the results of tests carried out by the built-in test device of the item of equipment, the nature of the operating anomalies of the item of equipment which have been signalled to the main computer by the built-in test devices of other equipment as well as the applicable configuration of the system.
A first known solution for alleviating the drawbacks exhibited by “intelligent systems” is maintenance management based on employing radio tags (or “RFID Tag” or else “Radio-Frequency Identification Tag”). A radio tag is a passive component which has the ability to store information and to communicate it, on request, by means of a contactless link, in general in the radio frequency span.
When such a radio tag, in which a configuration information cue relating to an item of equipment has been stored beforehand, is stuck on the item of equipment, it allows a maintenance team equipped with a radio tag reader to access the configuration information cue relating to the item of equipment, even when the item of equipment is not supplied with power, doing so without resorting to a test bench.
However, the radio tag stuck on an item of equipment does not make it possible to gather all the results of tests carried out by the built-in test device of the item of equipment.
Specifically, the frequency span of the contactless link making it possible to communicate with the radio tag, in general in the radio region, is not suited to a communication over a range exceeding a metre, in an environment that may consist of surfaces made of electrical conducting materials. Maintenance management based solely on employing a radio tag fixed to equipment therefore does not constitute a solution to the problem of communication and then storage of all the results of tests carried out by the test devices built into radio tags.